Stacking apparatus for sheet material



Jan. 16, 1962 H. BOBST STACKING APPARATUS FOR SHEET MATERIAL Filed July9, 1957 3 Sheets-Sheet 1 Jan. 16, 1962 H. BOBST STACKING APPARATUS FORSHEET MATERIAL 3 Sheets-Sheet 2 Filed July 9, 1957 Jan. 16, 1962 o s3,017,040

STACKING APPARATUS FOR SHEET MATERIAL Filed July 9, 1957 3 Sheets-Sheet3 United States Patent ()fifice BJHZM-d Patented Jan. 18, 1962 3 $17,040STACKKNG APPARAT US FQR SHEET MATERIAL Henri Bohst, Lausanne,Switzerland, assignor to J. Bobst and Son A., a corporation ofwitzerland Filed duty 9, 1957, Ser. No. 676,776 1 Claim. (Ci. 214-6) Thepresent invention relates to a punching press for sheet material such aspaper or cardboard.

In presses of this type, after the punching operation the resultingblanks are generally freed from the waste before being ejected. In thiscase, the press includes, besides the actual operation station, areception station and other stations where part or all of the waste isejected.

The press according to the present invention, whether of one or theother of the types under consideration, is fitted with a mobile deviceconsisting of a retractable support intended to receive a pile of workedpieces and with a conveying device receiving and evacuating the pileeach time the support retracts and the pile falls upon the conveyorwhich, owing to its mobility and dimensions, is convenient for mountingthe retractable support in any position chosen under the receivingstation of the worked pieces. Further, a counter of the worked pieces isprovided, for causing the temporary retraction of the support wheneverthe pile heaped upon it reaches a pre-determined number of pieces.

The main advantage of the above arrangement consists in the fact thatthe reception of the worked pieces can be efiected as required, not onlyin counted bundles, but also continuously, that is to say, without itbeing necessary to interrupt the working of the press, as is the casewhen removing single piles of pieces received on a tray which drops downgradually as the pile is formed. Furthermore, the mobility of the devicepermits, on the one hand, the complete elimination of this device when aconventional method of reception is used, and, on the other hand,according to the type of press, the setting of the device at will underany one of the stations which functions at the time as a receiving postwith, in addition, the possibility of placing the device in such a waythat the retractable support is always in a suitable position withrespect to the size of the worked pieces to be received.

The annexed drawing represents an embodiment of the invention given byway of example in the case of a press in which the location of thereceiving station can vary according to the method of work adopted. Apress of this type is described more fully in co-pending applicationSerial Number 586,018.

FIG. 1 is a schematic side elevation view of the press mentioned aboveand shows how a device embodying the present invention may be associatedtherewith; FIG. 2 is a diagrammatic side elevational view of the deviceof FIG. 1, but on a larger scale; FIG. 3 is a half side elevation of anaccessory which is useful in connection with the device of FIG. 2; andFIG. 4 is a half elevation of the accessory of FIG. 3.

The press shown by way of example in FIG. 1 consists of the base 1,containing mechanism which is not shown here and not part of theinvention, but which operates as follows:

At station A, punching the sheets between platens;

At station E, ejecting all waste with the exception of part of the sheetby means of which the punched piece is held for feeding into themachine, the ejected waste falling in the direction of arrow 2 on to amoving inclined plane 3;

At station C, called the reception station, ejecting the piecesthemselves, which are freed from their waste and fall in the directionof arrow 4 and form a pile 5;

At station .1), finally, ejecting in the direction of arrow 6, thatwaste part of the sheet by which the piece ejected at station C wasconveyed, this waste part falling on to a transverse conveyor belt 7.

Generally speaking, the sheets are registered before arriving at pointA, and are conveyed from one position to the other by means of gripperbars driven by endless chains 8 which are periodically advanced.

It is obvious that any other continuous or intermittent method ofconveyance can be employed.

It should be noted that although in the above described operation of thepress, the finished pieces are ejected at station C, that is, the nextto the last station, whereas a certain amount of waste remains attachedto the gripper bars and such waste is ejected at the last station D, itwould also be possible to operate the press so that the sheets bearingthe finished pieces would be ejected at station D.

Pile 5 formed by the pieces falling in the direction of arrow 4 rests ona moving device consisting of a frame 9 mounted on wheels 10, thusenabling it to be displaced at will with respect to the press or even tobe removed altogether.

The pile 5 is supported on this device by means of two flaps 19 and 20placed transversely to the direction of displacement of the sheets inthe press and to the direction in which frame 9 may be moved under thelatter. These flaps are connected to rods 11 and 12 pivoted on the upperends of levers 13 and 14 which pivot around their lower ends.

The reference numeral 15 indicates a mechanism of any appropriate typewhich, by means of two rods 16 and 17, can cause levers 13 and 14 tooscillate temporarily by pushing them apart, that is to say by pushinglever 13 to the left and lever 14 to the right from the positionsthereof shown in FIG. 1 of the drawing.

This results in retraction of the two flaps holding pile 5 so that thelatter drops to the position indicated at 5 on a conveyor belt 23 whichextends along the whole length of the upper part of frame 9 and moves inthe direction of arrow 18 to convey the pile to the position indicatedat 5".

As shown in greater detail in FIG. 2, the flaps 19 and 20 extendingtransversally to the longitudinal and displacement axis of frame 9,slide horizontally in U-shaped channel members of the frame, asindicated at 21, and in which they are guided by rollers 22. The brokensection appearing on the right hand side of FIG. 2 shows thisarrangement in greater detail and at the same time the flap 2B is shownin a retracted position whereas flip 19 is in its normal position, inwhich .it supports the worked pieces forming pile Sin FIG. 1.

As already mentioned. the mechanism 15 serves to effect the temporaryretraction, i.e. the wi.hdrawal to th left and to the right, withreference to the positions in FIG. 1 of the drawing, of the flaps 19 and213. This mechanism can, for example, be an electro-motor coupled by asingle revolution clutch with two cranks connected with rods 16 and 17,and which is controlled by any suitable system to make the cranks eifecta complete revolution, that is to say a to-and-fro oscillation of thetwo levers 13 and 14.

The longitudinal conveyor belt 23 serving to convey the piles of piecesin the direction of arrow 18 can be continuously driven for instance byan electro-motor located at 24.

The finished pieces, once rid of their waste, fall in the direction ofarrow 4 fall upon the flaps 19 and 20, then on to the conveyor belt 23when the flaps retract.

Since the size of the sheets to be processed may vary, the piecesarranged in piles may be of various dimensions, according to the workperformed. Further, it is necessary that the median passing between thetwo adjacent edges of the flaps 19 and 20, when they are together,should pass practically beneath the center of the piled up pieces, sothat, at the moment of retraction, the pile is left unsupported by thetwo opposed edges simultaneously, otherwise the pile would be upset ortilted instead of falling fiat on to the conveyor belt. This isprecisely one of the advantages of the device being movable on wheels 10as has been described, since it enables the flaps 19 and 20 to be placedin proper position below the reception station. Once this position isattained it is retained during any given job, by a suitable lockingmeans for example, a pin 25 which is to be inserted into one of a seriesof holes which can be provided in the receiving plate of the press. Thisreceiving plate of the press may also carry rails to guide the wheels10.

Referring again to FIG. 1, it should be mentioned that somewhere on themachine there is to be provided a counter serving to record the numberof finished pieces falling upon the pile 5, the purpose of this counterbeing to actuate a part of the mechanism 15, which, for instance, can bethe single revolution clutch already mentioned. The counter actuatessuch clutch each time a pre-determined number of pieces falls upon thepile 5, that is to say whenever the flaps are to be retracted to dropthe pile at on to the conveyor belt 23, for instance for each lot often, fifteen or twenty pieces delivered and piled.

The counter can be either mechanical, electrical or photo-electrical andshould preferably be placed on the press and be able to act upon themechanism both mechanically and electrically.

At high speeds, however, an absolute synchronization must exist betweenthe rhythm at which the pieces fall in the direction of arrow 4 on tothe pile 5 and the instant when the flaps 19 and 20 are retracted so asto ensure that once the pile has dropped, the flaps are returned totheir normal position and are ready to receive the first sheet of thefollowing pile.

To ensure this synchronization, the counter can be made to close anelectrical circuit controlling mechanism 15 upon the deposit of apredetermined number of pieces in pile 5, but this circuit must then beclosed by an additional switch controlled by an element of the mechanismof the press.

All the operations just described can naturally take place not onlybelow station C, but below stations B or D as well, in case one of thelatter i the receiving station, simply by shifting the device describedabove and positioning it where it is required for the reception of thesheets falling in piles in the direction of arrow 2 or arrow 6. Theassociated press may also have only two stations, namely stations A andB.

Since in the example described here the pieces are ejected at station Cwhile, at station D, the grippers of the bars conveying the sheetsthrough the press discard waste, it is apparent that such waste woulddrop either onto the conveyor belt 23 or onto a moving pile of pieces.

In order to avoid this, an accessory is provided formed by the frame 26mounted on wheels 27 and able to straddle the device previouslydescribed. The frame 26 has a transverse conveyor belt 7 intended forthe lateral evacuation of the waste ejected at station D.

FIGS. 3 and 4 show this straddle frame 26 on a larger scale and in thehalf views from the side and the front respectively. The frame 26 iprovided with its own motor, not shown in the drawing. Transport of thewaste can, for instance, be effected in the direction of arrow 28, withthe waste falling in the direction of 4 arrow 29 (FIG. 4), outside theprofile of the pilereceiving device, which is indicated X.

The foregoing description naturally applies to presses other than thetype specifically mentioned herein by way of example, and the device canbe used for the reception of pieces of paper or of cardboard, but it isparticularly suitable when the material is either a thick cardboard orpieces of corrugated cardboard.

Although it has been stated that the device fitted with retracting flaps19 and 20 and conveyor belt 23 extends in the direction of conveyance ofthe sheets across the press, obviously, the device might as well bedesigned for positioning at right angles to this direction. In thelatter case, the additional conveyor belt 7 of the frame 26 would nolonger be necessary.

What I claim is:

Apparatus for stacking and transporting flexible cut sheets receivedfrom the reception station of a punch press thereabove, comprising aframe movable to a position below the reception station of the punchpress, a continuously operable conveyor carried by said frame fortransporting stacks of the cut sheets fromunder the reception station, apair of horizontal flaps, means supporting said flaps on said frame in ahorizontal plane above said conveyor and guiding said flaps forsimultaneous movements toward and away from each other in saidhorizontal plane between closed positions, wherein said flaps arejuxtaposed to intercept and support the successive cut sheets fallingfrom the reception station and, thus, forming a stack of sheets on saidflaps, said flaps cooperatively supporting said flexible sheets in astack of juxtaposed horizontal planes and retracted positions, whereinsaid flaps are relatively widely spaced apart simultaneously andinstantaneously to permit the stack of cut sheets previously formed onthe flaps to fall evenly and undeformed between the latter onto theunderlying conveyor, and means for intermittently efiecting the movementof said flaps from said closed positions to said retracted positions andthen back to said closed positions for again intercepting and supportingthe cut sheets falling from said reception station, said means forintermittently effecting the movement of the flaps including leverspivotally supported at their lower ends for swinging movements invertical planes parallel to the directions of movement of the flapsbetween said closed and retracted positions, links pivotally connectedat their opposite ends to the upper ends of said levers and to saidflaps, respectively, so that said flaps move between said closed andretracted positions in response to rocking of said levers toward andaway from each other, and means for simultaneously rocking said levers.

References Cited in the file of this patent UNITED STATES PATENTS1,466,177 Lacke Aug. 28, 1923 1,600,958 Hart et al. Sept. 21, 19262,000,273 Conklin et al. May 7, 1935 2,424,093 Harred July 15, 19472,488,675 Mallot Nov. 22, 1949 2,615,376 Pelikan Oct. 28, 1952 2,627,354Isella et al. Feb. 3, 1953 2,701,650 Stevenson Feb. 8, 1955 2,710,696Fontaine et al. June 14, 1955 2,793,693 Menk May 28, 1957 2,947,428Curtenius Aug. 2, 1960 FOREIGN PATENTS 905,356 Germany Mar. 1, 1954

